Hello,
No question is stupid if you intend to learn :)
IP Aliases are a way of defining or reaching a subnet that works in the same space as the regular network. This is useful if you need to reach the router that is located in the same network but in a different subnet. If you have a static IP configuration on your computer and don’t want to change it every time you need to reach a router in a different subnet, you can configure an IP alias in order to do so.
As you can see, the configuration is very similar to the static protocol; in the example above an IP address with a 99th subnet is defined. In this case, if some device has an IP in the 99th subnet (e.g., 192.168.99.xxx) and the subnet’s gateway metric is “higher” and the device is trying to reach the internet it will reroute it’s traffic not to the gateway that is defined in common configurations but through the one that is specified in IP aliases.
Please let me if this clarifes it or not, feel free to send me a pm.